Purpose

To consolidate, disseminate, and gather information concerning the 710 expansion into our San Rafael neighborhood and into our surrounding neighborhoods. If you have an item that you would like posted on this blog, please e-mail the item to Peggy Drouet at pdrouet@earthlink.net

Wednesday, October 23, 2013

Beyond “Level of Service” — New Methods for Evaluating Streets

Streetsblog reported earlier this month
that transportation agencies are increasingly aware of the insidious
consequences of using “Level of Service” as the primary metric for their
projects. Because Level of Service only rewards the movement of motor
vehicles, it promotes dangerous, high-speed streets and sprawling land
use.

The question remains: How should streets and development projects be measured?

If
this is what you want for your street, Level of Service won't get you
there. You need a different performance measure.

We mentioned
that some places are switching to an analysis called multi-modal Level
of Service. But Jeffrey Tumlin, a consultant with Nelson\Nygaard, says
there are problems with that approach as well.

Multi-modal Level of Service, he says, takes “all of the narrow
thinking around delay for cars and applies that same thinking to all the
other modes.” For example, MM-LOS assumes pedestrians and transit
riders have the same need as vehicles: “lack of congestion,” or space
between others who travel the same way.

But what works for cars isn’t necessarily what works for other modes.
For example, MM-LOS views “transit crowding” as a wholly negative
thing. On this measure, an infill development might be penalized for
leading to “crowding,” but a sprawling greenfield development would face
no penalty, since it would produce fewer transit riders.

According to Tumlin, searching for a direct replacement for Level of
Service is the wrong way to go, because part of the problem with Level
of Service is the narrowness of its scope.

“LOS tells us about one thing [vehicle delay at intersections], but
it doesn’t tell us about anything else,” says Tumlin. “What are all of
the things we want our transportation system to do, and how do we
measure whether it’s doing that or not?”

Tumlin’s advice to transportation professionals and public officials
is to adopt performance measures based on expressed community values as
well as the specifics of the project at hand.

For example, Tumlin said if he were designing an industrial park,
Level of Service for trucks might be a primary performance measure. But
on a retail street where economic development is the goal, parking
availability or pedestrian friendliness might be the targeted
performance measure.

If
women feel safe walking on a commercial street at night, that's a great
predictor of retail success, says Jeffrey Tumlin.

“Pedestrian Level of Service and quality of service is a very complex
science,” said Tumlin. “The things that pedestrians care about are
comfort, the frequency of pedestrian crossings, how long they have to
wait for a green. Some of the most important factors are really related
to urban design and are very subjective.”

For measures like that, local governments and transportation agencies
can survey local residents, Tumlin says. In fact, one of the best
determinants of a healthy retail area, researchers have found, is the
comfort level of women.

“If women felt safe there walking at night, [the street] was going to
be comfortable for every mode, it was going to have high property
values and retail success,” Tumlin said.

Ronald Milam, a consultant with Fehr and Peers, was part of a
statewide committee in California that studied alternatives to LOS for
Governor Jerry Brown’s Office of Planning. Milam is also the author of
the e-book, LOS Gets a Failing Grade.

Most communities — even the most transit-rich, like San Francisco —
continue to use Level of Service in some of their engineering, Milam
says. But many California communities are bringing in new performance
measures and reducing their focus on LOS.

Yolo County explicitly allows Level of Service “F” because the
community prioritizes walkability over the speed of drivers. Yolo County
also implemented a vehicle-miles-traveled threshold. For new housing
developments, the county targeted projects that would generate less than
44 vehicle miles traveled per household per day.

One benefit of LOS is that it tells you how the user perceives the
system, albeit only one kind of user: drivers. What LOS won’t tell you
is how the system is performing overall.

Rather than examine LOS at each individual intersection in isolation,
Milam says, the city of Pasadena looks at network-wide vehicle speeds
as a leading performance measure. Network speed also tells you what you
can expect when it comes to the severity of collisions, so in certain
areas, like pedestrian districts, low speeds might be targeted.

Accessibility
is another important performance metric. ”‘How close are the things you
need?’ is a pretty important thing for us to be thinking about and
planning.” Milam said. “You can solve an accessibility problem with
either a transportation or a land use solution.”

Measuring the vehicle mileage generated by new development is another
useful metric that several California communities are using.
Traditional LOS gives preference to new developments in sprawling
greenfield locations because they disperse vehicle traffic over a broad
area, reducing congestion at any one intersection. But add up all those
developments and the effect of that strategy is to encourage more
driving overall, worsening congestion. A VMT measure, on the other hand,
gives preference to projects in locations that lead to shorter and
fewer vehicle trips.

In short, Tumlin says, the answer is to “stop fixating on this one metric” — Level of Service.
“Transportation performance measures are very important and they need
to be simple enough to be understandable,” he said, “but they need to
reflect all of the goals that we want our entire transportation system
to achieve.”